Use the numbers 2, 3, 4 and 5 and the symbols + and = to make a true equation. Conditions: Each must be used exactly once and no other numbers or symbols can be used.

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

What is next number in the pattern below:

131 517 192 123 ?

How many triangles are there on the puzzle below?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

I have two coins.
* One of the coins is a faulty coin having a tail on both sides of it.
* The other coin is a perfect coin (heads on side and tail on other).

I blindfold myself and pick a coin and put the coin on the table. The face of the coin towards the sky is the tail.

What is the probability that another side is also tail?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

Using Only Five 5's and any mathematical operator make sum as 37

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

By using all numbers, i.e. 123456789 and subtraction/addition, operators number 100 can be formed in many ways.
Example: 98 + 7 + 6 - 5 - 4 - 3 + 2 - 1 = 100

But if we add a condition use of the number 32 is a must. Then there are limited solutions.
One of such solution is: 9 - 8 + 76 + 54 - 32 + 1 = 100

Can you tell me any other solution?